Integrated lead or wireless disk drive head suspensions and flexures commonly include structures having a relatively noncorrosive material such as gold and/or nickel that is plated or otherwise applied to the surface of a relatively more corrosive conductor such as copper or copper alloy. The gold is sometimes plated on the conductor through an opening in a polyimide or other dielectric layer. In structures of these types an edge of the gold plating can form a joint or interface with the dielectric. The Yonekura et al. U.S. Patent Application Publication 2013/0242436, for example, discloses in FIG. 19C a “backside access” flexure terminal having a structure of this type. The terminal face on a wiring layer is exposed by a through hole in a metal layer and an insulating layer, and the terminal face is gold plated.
Unfortunately, the joint between the gold plating and the dielectric layer in structures of these types is susceptible to separation. Any void or crevice that forms between the gold plating and dielectric can provide access to the conductor by moisture or other substances, leaving the conductor vulnerable to undesired corrosion. There is, therefore, a continuing need for improved structures having enhanced gold-to-dielectric joint reliability. Structures of these types that can be efficiently manufactured would be especially desirable.